softworkz .:
>
>
>> -----Original Message-----
>> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of
>> Andreas Rheinhardt
>> Sent: Dienstag, 15. April 2025 03:06
>> To: ffmpeg-devel@ffmpeg.org
>> Subject: Re: [FFmpeg-devel] [PATCH 2/9] fftools/textformat: Quality
>> improvements
>>
>> softworkz:
>>> From: softworkz <softwo...@hotmail.com>
>>>
>>> Signed-off-by: softworkz <softwo...@hotmail.com>
>>> ---
>>> fftools/textformat/avtextformat.c | 121 +++++++++++++++++++--------
>> ---
>>> fftools/textformat/avtextformat.h | 6 +-
>>> fftools/textformat/tf_default.c | 8 +-
>>> fftools/textformat/tf_ini.c | 2 +-
>>> fftools/textformat/tf_json.c | 8 +-
>>> fftools/textformat/tf_xml.c | 3 -
>>> fftools/textformat/tw_avio.c | 9 ++-
>>> 7 files changed, 101 insertions(+), 56 deletions(-)
>>>
>>> diff --git a/fftools/textformat/avtextformat.c
>> b/fftools/textformat/avtextformat.c
>>> index 1ce51d11e2..406025d19d 100644
>>> --- a/fftools/textformat/avtextformat.c
>>> +++ b/fftools/textformat/avtextformat.c
>>> @@ -93,9 +93,8 @@ static const AVClass textcontext_class = {
>>>
>>> static void bprint_bytes(AVBPrint *bp, const uint8_t *ubuf, size_t
>> ubuf_size)
>>> {
>>> - int i;
>>> av_bprintf(bp, "0X");
>>> - for (i = 0; i < ubuf_size; i++)
>>> + for (unsigned i = 0; i < ubuf_size; i++)
>>
>> Why not size_t?
>
> Because it creates more warnings about narrowing conversions.
>
>
>
>>> av_bprintf(bp, "%02X", ubuf[i]);
>>> }
>>>
>>> @@ -110,8 +109,6 @@ int avtext_context_close(AVTextFormatContext
>> **ptctx)
>>>
>>> av_hash_freep(&tctx->hash);
>>>
>>> - av_hash_freep(&tctx->hash);
>>> -
>>> if (tctx->formatter->uninit)
>>> tctx->formatter->uninit(tctx);
>>> for (i = 0; i < SECTION_MAX_NB_LEVELS; i++)
>>> @@ -141,12 +138,18 @@ int avtext_context_open(AVTextFormatContext
>> **ptctx,
>>> AVTextFormatContext *tctx;
>>> int i, ret = 0;
>>>
>>> - if (!(tctx = av_mallocz(sizeof(AVTextFormatContext)))) {
>>> + if (!ptctx || !formatter)
>>> + return AVERROR(EINVAL);
>>
>> Can this happen?
>
> see below
>
>>> +
>>> + if (!formatter->priv_size && formatter->priv_class)
>>> + return AVERROR(EINVAL);
>>
>> Stuff like this should never happen and should not be checked (or
>> actually: the proper place to check stuff like this is in test tools
>> like lavc/tests/avcodec.c, but I don't think it is worth it for
>> fftools).
>
> I probably overdid it a bit with checks, but the goal for this API
> is still to become public at some point (like in avutil), so I
> tried to move towards that direction already.
>
>
>
>
>>> +
>>> + if (!((tctx = av_mallocz(sizeof(AVTextFormatContext))))) {
>>> ret = AVERROR(ENOMEM);
>>> goto fail;
>>> }
>>>
>>> - if (!(tctx->priv = av_mallocz(formatter->priv_size))) {
>>> + if (formatter->priv_size && !((tctx->priv =
>> av_mallocz(formatter->priv_size)))) {
>>> ret = AVERROR(ENOMEM);
>>> goto fail;
>>> }
>>> @@ -215,15 +218,15 @@ int avtext_context_open(AVTextFormatContext
>> **ptctx,
>>>
>>> /* validate replace string */
>>> {
>>> - const uint8_t *p = tctx->string_validation_replacement;
>>> - const uint8_t *endp = p + strlen(p);
>>> + const uint8_t *p = (uint8_t *)tctx-
>>> string_validation_replacement;
>>> + const uint8_t *endp = p + strlen((const char *)p);
>>> while (*p) {
>>> const uint8_t *p0 = p;
>>> int32_t code;
>>> ret = av_utf8_decode(&code, &p, endp, tctx-
>>> string_validation_utf8_flags);
>>> if (ret < 0) {
>>> AVBPrint bp;
>>> - av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
>>> + av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);
>>
>> This adds a memleak on data where it makes a difference.
>
> Why? The string_validation_replacement string should be short enough
> to fit into the stack-allocated memory, no?
>
>
>>> bprint_bytes(&bp, p0, p - p0),
>>> av_log(tctx, AV_LOG_ERROR,
>>> "Invalid UTF8 sequence %s found in
>> string validation replace '%s'\n",
>>> @@ -259,6 +262,9 @@ static const char unit_bit_per_second_str[] =
>> "bit/s";
>>>
>>> void avtext_print_section_header(AVTextFormatContext *tctx, const
>> void *data, int section_id)
>>> {
>>> + if (!tctx || section_id < 0 || section_id >= tctx->nb_sections)
>>> + return;
>>
>> Can this happen?
>
> For a public API - many things can happen...
>
>
>>> tctx->level++;
>>> av_assert0(tctx->level < SECTION_MAX_NB_LEVELS);
>>>
>>> @@ -272,6 +278,9 @@ void
>> avtext_print_section_header(AVTextFormatContext *tctx, const void
>> *data, in
>>>
>>> void avtext_print_section_footer(AVTextFormatContext *tctx)
>>> {
>>> + if (!tctx || tctx->level < 0 || tctx->level >=
>> SECTION_MAX_NB_LEVELS)
>>> + return;
>>
>> Can this happen?
>
> Yes - when somewhere in FFmpeg some output is changed without thinking
> about that there's a nesting limit of SECTION_MAX_NB_LEVELS.
> Even when only 2 or 3 section types are defined, the level can go beyond
> that value.
>
>
>>
>>> +
>>> int section_id = tctx->section[tctx->level]->id;
>>> int parent_section_id = tctx->level
>>> ? tctx->section[tctx->level - 1]->id
>>> @@ -289,7 +298,12 @@ void
>> avtext_print_section_footer(AVTextFormatContext *tctx)
>>>
>>> void avtext_print_integer(AVTextFormatContext *tctx, const char
>> *key, int64_t val)
>>> {
>>> - const struct AVTextFormatSection *section = tctx->section[tctx-
>>> level];
>>> + const AVTextFormatSection *section;
>>> +
>>> + if (!tctx || !key || tctx->level < 0 || tctx->level >=
>> SECTION_MAX_NB_LEVELS)
>>> + return;
>>
>> Can this happen?
>
>
> see above
>
>
>>
>>> +
>>> + section = tctx->section[tctx->level];
>>>
>>> if (section->show_all_entries || av_dict_get(section-
>>> entries_to_show, key, NULL, 0)) {
>>> tctx->formatter->print_integer(tctx, key, val);
>>> @@ -299,24 +313,28 @@ void avtext_print_integer(AVTextFormatContext
>> *tctx, const char *key, int64_t va
>>>
>>> static inline int validate_string(AVTextFormatContext *tctx, char
>> **dstp, const char *src)
>>> {
>>> - const uint8_t *p, *endp;
>>> + const uint8_t *p, *endp, *srcp = (const uint8_t *)src;
>>> AVBPrint dstbuf;
>>> + AVBPrint bp;
>>> int invalid_chars_nb = 0, ret = 0;
>>>
>>> + if (!tctx || !dstp || !src)
>>> + return AVERROR(EINVAL);
>>> +
>>
>> Can this happen?
>>
>>> + *dstp = NULL;
>>> av_bprint_init(&dstbuf, 0, AV_BPRINT_SIZE_UNLIMITED);
>>> + av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);
>>>
>>> - endp = src + strlen(src);
>>> - for (p = src; *p;) {
>>> - uint32_t code;
>>> + endp = srcp + strlen(src);
>>> + for (p = srcp; *p;) {
>>> + int32_t code;
>>> int invalid = 0;
>>> const uint8_t *p0 = p;
>>>
>>> if (av_utf8_decode(&code, &p, endp, tctx-
>>> string_validation_utf8_flags) < 0) {
>>> - AVBPrint bp;
>>> - av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
>>> - bprint_bytes(&bp, p0, p-p0);
>>> - av_log(tctx, AV_LOG_DEBUG,
>>> - "Invalid UTF-8 sequence %s found in string
>> '%s'\n", bp.str, src);
>>> + av_bprint_clear(&bp);
>>> + bprint_bytes(&bp, p0, p - p0);
>>> + av_log(tctx, AV_LOG_DEBUG, "Invalid UTF-8 sequence %s
>> found in string '%s'\n", bp.str, src);
>>> invalid = 1;
>>> }
>>>
>>> @@ -336,7 +354,7 @@ static inline int
>> validate_string(AVTextFormatContext *tctx, char **dstp, const
>>> }
>>>
>>> if (!invalid || tctx->string_validation ==
>> AV_TEXTFORMAT_STRING_VALIDATION_IGNORE)
>>> - av_bprint_append_data(&dstbuf, p0, p-p0);
>>> + av_bprint_append_data(&dstbuf, (const char *)p0, p -
>> p0);
>>> }
>>>
>>> if (invalid_chars_nb && tctx->string_validation ==
>> AV_TEXTFORMAT_STRING_VALIDATION_REPLACE)
>>> @@ -346,6 +364,7 @@ static inline int
>> validate_string(AVTextFormatContext *tctx, char **dstp, const
>>>
>>> end:
>>> av_bprint_finalize(&dstbuf, dstp);
>>> + av_bprint_finalize(&bp, NULL);
>>> return ret;
>>> }
>>>
>>> @@ -358,17 +377,18 @@ struct unit_value {
>>> const char *unit;
>>> };
>>>
>>> -static char *value_string(AVTextFormatContext *tctx, char *buf, int
>> buf_size, struct unit_value uv)
>>> +static char *value_string(const AVTextFormatContext *tctx, char
>> *buf, int buf_size, struct unit_value uv)
>>> {
>>> double vald;
>>> - int64_t vali;
>>> + int64_t vali = 0;
>>> int show_float = 0;
>>>
>>> if (uv.unit == unit_second_str) {
>>> vald = uv.val.d;
>>> show_float = 1;
>>> } else {
>>> - vald = vali = uv.val.i;
>>> + vald = (double)uv.val.i;
>>> + vali = uv.val.i;
>>> }
>>>
>>> if (uv.unit == unit_second_str && tctx-
>>> use_value_sexagesimal_format) {
>>> @@ -387,17 +407,17 @@ static char *value_string(AVTextFormatContext
>> *tctx, char *buf, int buf_size, st
>>> int64_t index;
>>>
>>> if (uv.unit == unit_byte_str && tctx-
>>> use_byte_value_binary_prefix) {
>>> - index = (int64_t) (log2(vald)) / 10;
>>> - index = av_clip(index, 0,
>> FF_ARRAY_ELEMS(si_prefixes) - 1);
>>> + index = (int64_t)(log2(vald) / 10);
>>> + index = av_clip64(index, 0,
>> FF_ARRAY_ELEMS(si_prefixes) - 1);
>>> vald /= si_prefixes[index].bin_val;
>>> prefix_string = si_prefixes[index].bin_str;
>>> } else {
>>> - index = (int64_t) (log10(vald)) / 3;
>>> - index = av_clip(index, 0,
>> FF_ARRAY_ELEMS(si_prefixes) - 1);
>>> + index = (int64_t)(log10(vald) / 3);
>>> + index = av_clip64(index, 0,
>> FF_ARRAY_ELEMS(si_prefixes) - 1);
>>> vald /= si_prefixes[index].dec_val;
>>> prefix_string = si_prefixes[index].dec_str;
>>> }
>>> - vali = vald;
>>> + vali = (int64_t)vald;
>>> }
>>>
>>> if (show_float || (tctx->use_value_prefix && vald !=
>> (int64_t)vald))
>>> @@ -425,9 +445,14 @@ void avtext_print_unit_int(AVTextFormatContext
>> *tctx, const char *key, int value
>>>
>>> int avtext_print_string(AVTextFormatContext *tctx, const char *key,
>> const char *val, int flags)
>>> {
>>> - const struct AVTextFormatSection *section = tctx->section[tctx-
>>> level];
>>> + const AVTextFormatSection *section;
>>> int ret = 0;
>>>
>>> + if (!tctx || !key || !val || tctx->level < 0 || tctx->level >=
>> SECTION_MAX_NB_LEVELS)
>>> + return AVERROR(EINVAL);
>>
>> Can this happen?
>>
>>> +
>>> + section = tctx->section[tctx->level];
>>> +
>>> if (tctx->show_optional_fields == SHOW_OPTIONAL_FIELDS_NEVER ||
>>> (tctx->show_optional_fields == SHOW_OPTIONAL_FIELDS_AUTO
>>> && (flags & AV_TEXTFORMAT_PRINT_STRING_OPTIONAL)
>>> @@ -462,7 +487,7 @@ int avtext_print_string(AVTextFormatContext
>> *tctx, const char *key, const char *
>>> void avtext_print_rational(AVTextFormatContext *tctx, const char
>> *key, AVRational q, char sep)
>>> {
>>> AVBPrint buf;
>>> - av_bprint_init(&buf, 0, AV_BPRINT_SIZE_AUTOMATIC);
>>> + av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
>>
>> This is strictly worse than what was here before: With UNLIMITED you
>> would have a memleak in case the internal buffer wouldn't suffice.
>> (But anyway, this should use snprintf. I just sent a patch for this.)
>
> To be honest, I don't see much value in AV_BPRINT_SIZE_AUTOMATIC.
> When I would need to check the return values of all bprint operations,
> all the convenience would go over board instantly. Using
> AV_BPRINT_SIZE_AUTOMATIC without return value checking is error-prone
> and can cause errors which might be hard to identify.
> On the other side, identifying places in code where AV_BPRINT_SIZE_UNLIMITED
> is used and finalize is needed is a lot easier and doesn't even need
> a specific case and/or debugging to find out.
>
> In the worst case, I'd still prefer a memory leak over incorrect
> behavior (or well - always depends on the case). By that I don't mean
> errors that are reported and causing failure but those things that are
> failing silently and are hard to notice or trace back when noticing.
>
> Surely others may see it differently.
>
>
>
>>
>>> av_bprintf(&buf, "%d%c%d", q.num, sep, q.den);
>>> avtext_print_string(tctx, key, buf.str, 0);
>>> }
>>> @@ -470,12 +495,11 @@ void avtext_print_rational(AVTextFormatContext
>> *tctx, const char *key, AVRationa
>>> void avtext_print_time(AVTextFormatContext *tctx, const char *key,
>>> int64_t ts, const AVRational *time_base, int
>> is_duration)
>>> {
>>> - char buf[128];
>>> -
>>> if ((!is_duration && ts == AV_NOPTS_VALUE) || (is_duration &&
>> ts == 0)) {
>>> avtext_print_string(tctx, key, "N/A",
>> AV_TEXTFORMAT_PRINT_STRING_OPTIONAL);
>>> } else {
>>> - double d = ts * av_q2d(*time_base);
>>> + char buf[128];
>>> + double d = av_q2d(*time_base) * (double)ts;
>>
>> We actually try to avoid explicit casts where possible.
>
>
> I'll answer that separately.
>
>
>
>>> struct unit_value uv;
>>> uv.val.d = d;
>>> uv.unit = unit_second_str;
>>> @@ -496,7 +520,8 @@ void avtext_print_data(AVTextFormatContext
>> *tctx, const char *name,
>>> const uint8_t *data, int size)
>>> {
>>> AVBPrint bp;
>>> - int offset = 0, l, i;
>>> + unsigned offset = 0;
>>> + int l, i;
>>>
>>> av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);
>>> av_bprintf(&bp, "\n");
>>> @@ -523,25 +548,29 @@ void avtext_print_data(AVTextFormatContext
>> *tctx, const char *name,
>>> void avtext_print_data_hash(AVTextFormatContext *tctx, const char
>> *name,
>>> const uint8_t *data, int size)
>>> {
>>> - char *p, buf[AV_HASH_MAX_SIZE * 2 + 64] = { 0 };
>>> + char buf[AV_HASH_MAX_SIZE * 2 + 64] = { 0 };
>>> + int len;
>>>
>>> if (!tctx->hash)
>>> return;
>>>
>>> av_hash_init(tctx->hash);
>>> av_hash_update(tctx->hash, data, size);
>>> - snprintf(buf, sizeof(buf), "%s:", av_hash_get_name(tctx-
>>> hash));
>>> - p = buf + strlen(buf);
>>> - av_hash_final_hex(tctx->hash, p, buf + sizeof(buf) - p);
>>> + len = snprintf(buf, sizeof(buf), "%s:", av_hash_get_name(tctx-
>>> hash));
>>> + av_hash_final_hex(tctx->hash, (uint8_t *)&buf[len],
>> (int)sizeof(buf) - len);
>>
>> Is it guaranteed that the output of snprintf() is not truncated?
>
> MAX_HASH_NAME_SIZE is 11 and AV_HASH_MAX_SIZE 64, make 192 - 11 > 0
>
>
>>
>>> avtext_print_string(tctx, name, buf, 0);
>>> }
>>>
>>> void avtext_print_integers(AVTextFormatContext *tctx, const char
>> *name,
>>> - uint8_t *data, int size, const
>> char *format,
>>> - int columns, int bytes, int
>> offset_add)
>>> + uint8_t *data, int size, const char
>> *format,
>>> + int columns, int bytes, int offset_add)
>>> {
>>> AVBPrint bp;
>>> - int offset = 0, l, i;
>>> + unsigned offset = 0;
>>> + int l, i;
>>> +
>>> + if (!name || !data || !format || columns <= 0 || bytes <= 0)
>>> + return;
>>
>> Can this happen?
>
> Sure, as a public API. Of course, one can spend time, trying to determine
> which conditions are realistically possible or not. But that introduces
> potential of human error, so - unless it's a really hot path, one check
> to many is better than one too less.
>
>
>>
>>>
>>> av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);
>>> av_bprintf(&bp, "\n");
>>> @@ -607,12 +636,18 @@ int
>> avtextwriter_context_open(AVTextWriterContext **pwctx, const
>> AVTextWriter *w
>>> AVTextWriterContext *wctx;
>>> int ret = 0;
>>>
>>> - if (!(wctx = av_mallocz(sizeof(AVTextWriterContext)))) {
>>> + if (!pwctx || !writer)
>>> + return AVERROR(EINVAL);
>>> +
>>> + if (!writer->priv_size && writer->priv_class)
>>
>> Stuff like this should never happen and should therefore not be
>> checked.
>
> OK.
>
>>
>>> + return AVERROR(EINVAL);
>>> +
>>> + if (!((wctx = av_mallocz(sizeof(AVTextWriterContext))))) {
>>> ret = AVERROR(ENOMEM);
>>> goto fail;
>>> }
>>>
>>> - if (!(wctx->priv = av_mallocz(writer->priv_size))) {
>>> + if (writer->priv_size && !((wctx->priv = av_mallocz(writer-
>>> priv_size)))) {
>>> ret = AVERROR(ENOMEM);
>>> goto fail;
>>> }
>>> diff --git a/fftools/textformat/avtextformat.h
>> b/fftools/textformat/avtextformat.h
>>> index 03564d14a7..e519094f4f 100644
>>> --- a/fftools/textformat/avtextformat.h
>>> +++ b/fftools/textformat/avtextformat.h
>>> @@ -21,9 +21,7 @@
>>> #ifndef FFTOOLS_TEXTFORMAT_AVTEXTFORMAT_H
>>> #define FFTOOLS_TEXTFORMAT_AVTEXTFORMAT_H
>>>
>>> -#include <stddef.h>
>>> #include <stdint.h>
>>> -#include "libavutil/attributes.h"
>>> #include "libavutil/dict.h"
>>> #include "libavformat/avio.h"
>>> #include "libavutil/bprint.h"
>>> @@ -103,7 +101,7 @@ struct AVTextFormatContext {
>>> unsigned int
>> nb_item_type[SECTION_MAX_NB_LEVELS][SECTION_MAX_NB_SECTIONS];
>>>
>>> /** section per each level */
>>> - const struct AVTextFormatSection
>> *section[SECTION_MAX_NB_LEVELS];
>>> + const AVTextFormatSection *section[SECTION_MAX_NB_LEVELS];
>>> AVBPrint section_pbuf[SECTION_MAX_NB_LEVELS]; ///< generic
>> print buffer dedicated to each section,
>>> /// used by
>> various formatters
>>>
>>> @@ -124,7 +122,7 @@ struct AVTextFormatContext {
>>> #define AV_TEXTFORMAT_PRINT_STRING_VALIDATE 2
>>>
>>> int avtext_context_open(AVTextFormatContext **ptctx, const
>> AVTextFormatter *formatter, AVTextWriterContext *writer_context, const
>> char *args,
>>> - const struct AVTextFormatSection *sections,
>> int nb_sections,
>>> + const AVTextFormatSection *sections, int
>> nb_sections,
>>> int show_value_unit,
>>> int use_value_prefix,
>>> int use_byte_value_binary_prefix,
>>> diff --git a/fftools/textformat/tf_default.c
>> b/fftools/textformat/tf_default.c
>>> index 14ef9fe8f9..3b05d25f36 100644
>>> --- a/fftools/textformat/tf_default.c
>>> +++ b/fftools/textformat/tf_default.c
>>> @@ -70,9 +70,10 @@ DEFINE_FORMATTER_CLASS(default);
>>> /* lame uppercasing routine, assumes the string is lower case ASCII
>> */
>>> static inline char *upcase_string(char *dst, size_t dst_size, const
>> char *src)
>>> {
>>> - int i;
>>> + unsigned i;
>>> +
>>
>> Why not size_t?
>
> see above.
>
>>
>>> for (i = 0; src[i] && i < dst_size - 1; i++)
>>> - dst[i] = av_toupper(src[i]);
>>> + dst[i] = (char)av_toupper(src[i]);
>>> dst[i] = 0;
>>> return dst;
>>> }
>>> @@ -108,6 +109,9 @@ static void
>> default_print_section_footer(AVTextFormatContext *wctx)
>>> const struct AVTextFormatSection *section = wctx->section[wctx-
>>> level];
>>> char buf[32];
>>>
>>> + if (!section)
>>> + return;
>>
>> Can this happen?
>
> No, but here it should actually call the function in tf_internal and with
> that it can happen. This must have gotten lost from rebasing.
>
>
>>> +
>>> if (def->noprint_wrappers || def->nested_section[wctx->level])
>>> return;
>>>
>>> diff --git a/fftools/textformat/tf_ini.c
>> b/fftools/textformat/tf_ini.c
>>> index 9e1aa60e09..ec471fd480 100644
>>> --- a/fftools/textformat/tf_ini.c
>>> +++ b/fftools/textformat/tf_ini.c
>>> @@ -92,7 +92,7 @@ static char *ini_escape_str(AVBPrint *dst, const
>> char *src)
>>> /* fallthrough */
>>> default:
>>> if ((unsigned char)c < 32)
>>> - av_bprintf(dst, "\\x00%02x", c & 0xff);
>>> + av_bprintf(dst, "\\x00%02x", (unsigned char)c);
>>> else
>>> av_bprint_chars(dst, c, 1);
>>> break;
>>> diff --git a/fftools/textformat/tf_json.c
>> b/fftools/textformat/tf_json.c
>>> index 24838b35ec..f286838d3c 100644
>>> --- a/fftools/textformat/tf_json.c
>>> +++ b/fftools/textformat/tf_json.c
>>> @@ -82,13 +82,18 @@ static const char *json_escape_str(AVBPrint
>> *dst, const char *src, void *log_ctx
>>> static const char json_subst[] = { '"', '\\', 'b', 'f',
>> 'n', 'r', 't', 0 };
>>> const char *p;
>>>
>>> + if (!src) {
>>> + av_log(log_ctx, AV_LOG_ERROR, "json_escape_str: NULL source
>> string\n");
>>> + return NULL;
>>> + }
>>
>> Can this even happen?
>>
>>> +
>>> for (p = src; *p; p++) {
>>> char *s = strchr(json_escape, *p);
>>> if (s) {
>>> av_bprint_chars(dst, '\\', 1);
>>> av_bprint_chars(dst, json_subst[s - json_escape], 1);
>>> } else if ((unsigned char)*p < 32) {
>>> - av_bprintf(dst, "\\u00%02x", *p & 0xff);
>>> + av_bprintf(dst, "\\u00%02x", (unsigned char)*p);
>>> } else {
>>> av_bprint_chars(dst, *p, 1);
>>> }
>>> @@ -107,6 +112,7 @@ static void
>> json_print_section_header(AVTextFormatContext *wctx, const void *dat
>>> wctx->section[wctx->level-1] : NULL;
>>>
>>> if (wctx->level && wctx->nb_item[wctx->level-1])
>>> + if (wctx->level && wctx->nb_item[wctx->level - 1])
>>> writer_put_str(wctx, ",\n");
>>>
>>> if (section->flags & AV_TEXTFORMAT_SECTION_FLAG_IS_WRAPPER) {
>>> diff --git a/fftools/textformat/tf_xml.c
>> b/fftools/textformat/tf_xml.c
>>> index 76271dbaa6..eceeda81e5 100644
>>> --- a/fftools/textformat/tf_xml.c
>>> +++ b/fftools/textformat/tf_xml.c
>>> @@ -18,10 +18,7 @@
>>> * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>> 02110-1301 USA
>>> */
>>>
>>> -#include <limits.h>
>>> -#include <stdarg.h>
>>> #include <stdint.h>
>>> -#include <stdio.h>
>>> #include <string.h>
>>>
>>> #include "avtextformat.h"
>>> diff --git a/fftools/textformat/tw_avio.c
>> b/fftools/textformat/tw_avio.c
>>> index d335d35a56..3c7492aa06 100644
>>> --- a/fftools/textformat/tw_avio.c
>>> +++ b/fftools/textformat/tw_avio.c
>>> @@ -63,7 +63,7 @@ static void io_w8(AVTextWriterContext *wctx, int
>> b)
>>> static void io_put_str(AVTextWriterContext *wctx, const char *str)
>>> {
>>> IOWriterContext *ctx = wctx->priv;
>>> - avio_write(ctx->avio_context, str, strlen(str));
>>> + avio_write(ctx->avio_context, (const unsigned char *)str,
>> (int)strlen(str));
>>> }
>>>
>>> static void io_printf(AVTextWriterContext *wctx, const char *fmt,
>> ...)
>>> @@ -89,10 +89,12 @@ const AVTextWriter avtextwriter_avio = {
>>>
>>> int avtextwriter_create_file(AVTextWriterContext **pwctx, const
>> char *output_filename, int close_on_uninit)
>>> {
>>> + if (!pwctx || !output_filename || !output_filename[0])
>>> + return AVERROR(EINVAL);
>>
>> Can this happen?
>
> When public - yes.
Can it happen now?
>
>
> Generally, I wonder: don't you find it risky to make decisions about
> function implementations that are based on knowledge about the calling
> code? ("can this happen?")
> I mean, the calling code doesn't know about the assumptions you
> were making and on which behavior the implementation might be relying on.
Not providing a pointer to store the AVTextWriterContext* is insane and
a programmer error. It should never happen. Doing so should lead to
undefined behavior (just as e.g. passing a NULL pointer to strlen()
does), even when public.
>
> For this patchset - most importantly for everything in graphprint.c,
> I had worked with the deliberate intention for checking everything that
> can be checked.
You should rather look at the callsites and ensure that they don't call
these functions in an insane way.
The motivation here is the fact that graph-printing
> is always run (when configured), even when the FFmpeg run has failed
> or errored, because those are often the most interesting cases for
> viewing the graph or getting the data.
> But in case of errors and abortion, we cannot make any assumptions
> anymore and the answer to "can this happen?" might be more often "yes"
> than usual.
Of course we can make assumptions. All we need to do is check the ones
that can happen at the call site. Where they belong.
>
> I hope you don't mind to postpone the removal of checks a little bit.
"Removal of checks"? This patch is about adding checks. Checks which IMO
should not be there in the first place.
> It doesn't feel right to me now, to go over and just blindly remove
> all of them. I would rather like to discuss a strategy/pattern in this
> regard about which checks should be made at which places and where
> not, also in the light of possibly being promoted to a public API.
> Finally, I'd also like to hear Stefanos opinion - it's mostly his
> code that we're moving around here 😊
- Andreas
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